Electric torch



Oct. 27, 1931. USTER 1,828,778

ELECTRIC TORCH Filed July 25. 1929 2 Sheets-Sheet l Oct. 27, 1931'.

J. LISTER ELECTRIC TORCH Filed July 25, 1929 2 Sheets-Sheet 2 xi MM Patented Get. 27, 1931 JOHN LISTER, OF LONDON, ENGLAND, ASSIGNGR-TO THE Evan READY COMPANY (GREAT BRITAIN) LIMITED, or LONDON, ENGLAND i ELEcTB-Iomon on Application .filed missus-2e, Serial No. 380,805,

This invention consists in improvements in or relating to electric torches especially adapted for use 'ininflamm'able atmospheres A, including petrolvapours'." c 1 k "According to the present invention, atorch comprises a battery-container which is completely closed in a gas-tight manner, which has at least one gas-tight removable cap for v the insertion and removal of the battery and which has a switch whereof the movable member is available from outside the torch,

, but extends into the casing also in a gas tightmanner.

V referably, the movable switch-element passes through the removable cap and a secondremovable and gas-tight cap is also provided for giving access to the lamp bulb.

" In one preferred embodiment of the invention' each capthatis removable has means 0 for enabling it-to be locked in placeagainst unauthorized removal. j p In order that the invention may be more clearly understood, two preferred examples of the accompanying drawings,in which Figure 1 is a perspective external. view of one form seen from the switch end; Figure-2 is a cent-ral'longitudinal section of the torch shown in Figure 1; V Figure 3 is 'a section on the line 3-30 e' rw; v v Figure 4 is a perspective external view of a second form seen from the lamp end; Figure 5 is a side elevation of the torch shown in Figure"4, partly in section,

Figure 6 is a sectional view on an enlarged scale of a detail of the cap-locking means for the constructions shownin Figures 4 and5;; a v V s Figure 7 is an illustration of the key required, for manipulating the lockingmeans shown in;Figures4to6; v :Figure 8 is an enlarged-sectional detail of parts ofthetorch shown in Figures 4 and Figure v9 is a perspective view-of a detail, showing formationfof the. end' of the casing 10 employed in the c'onstructionillus- 'trated in Figures 4, 5 and 8'.

' ure s ,1 to "3, the vcasing formed with outwardly extending flanges 11 thereof will now be'desc'ribed with the aid tight-jamming close" metallic and aims Britain April is, 1929.

Like reference numerals indicate like parts" inthe several figures of thedrawin'gs.

In the first example, illustrated in Fig- '10 is cylindrical, is

inset slightl'y'from each end, and isopen at both ends. The two ends .ofthecasing which extend beyond the flanges 11 are both screwthreaded to engage correspondingly threaded portions ot'end-sclosure caps'13 and 14 respectively, each ofwhich is tormed with a flange 15 .wh'ch, when the cap is screwed into place, as shown in Figures 1 and 2, lies over the flange casing. V The end-cap l3 is itse'lf open-ended, andin the outer end there iszsecured a" cover-glass 16, preferabl of nonsplinterable or ply-glass,

and behind t ielatter there isa lamp-reflector 17 The :latter is centrally. perforated to pass over the incandescent electric lamp bulb 18 which is carried in a socket 19 formed in an insulating block 20 secure'd intheadja- .cent end of the casing 10.

The socketlt) is a metal one which is electrically'connected to the casing by means of a metal I or is otherwise metallically connected to the ocket 19 and eXte ds inwardly from a ring 23 that isiitself metallically connected. to thegcasing '10.

For instance, the ring 23 maybe either a fit in thee casing. 10, or it may be soldered or nested thereto. The lamp bulb 18, in this case, is intended to have a central terminal 24 which, when. the bulb is screwed into place in thesocket 19, will engage a conducting 11 on the appropriate end of the otherwise metallically con- 1 strip 21 that is formed integral with is 'also riveted to'a lug 22 that e.

strip 25, also carried on the insulating block 7 420. One end ofthestrip 2 5 is 'securedin a contact between, one end of a bridge-member 26 and the insulating block 20, and both ends-of the bridgefmember 26 are rivetedtothe insulating block. The free end of the strlp 25 will press resiliently against theielectrode 24 soas at all times to 'IIltLlIlllillIl good electrical 'contac't'therewith.

The other terminaljofthe lamp'bulb filament is constituted bythe screi 'ed 'met al' cap 27 which seatslin the socket '19}.

One pole 28 of a cylindrical battery 29, when the latter is inserted within the casing, will engage the bridge-member 26 and so be in electrical contact with the terminal 24 of the lamp. Electrical contact between the other pole of the battery and the metal cap 27 of the lamp is made through the casing 10 and through a switch that is located in the end of the casing that is closed by the cap 1 1.

The end-cap 14 has a closed outer endwall 30 formed with a screwthreaded central aperture through which passes a screwed pin 31 terminating at its outer end in a knurled head 32. At its inner end the pin 31 has a portion 33 of reduced diameter which is also screwthreaded and receives upon it a nut 34 which is screwed down on to the shoulder formed at the junction of the parts 31 and 33 so as to leave the extremity of the part 33 exposed beyond it. The nut 34: is inthe form of a flat discwhich is guided in a sleeve portion 35 formed integrally with the inner surface of the end-wall 30 of the cap 1 1.

Slidingly fitted within the end of the casin 10 adjacent the cap 14 is a hollow cylindrlcal block 36 of insulating material on which is mounted the usual tapering coiled spring '37, the inner end of which presses against the exposed metallic end of the battery 29 constituting the second pole thereof. The other end of the spring is secured be tween one head of a screw-b0lt 39 and a metal plate 38 which ishel-d to the face of the insulat-in block by means of the screw-bolt 39. The otl ier head 40 of this bolt appears centrally on the inner face of the insulating member and is presented towards the extensi0n33 of the screw-pin 31. As will be seen from the drawings, the concavity of the hollow block 36 is presented towards the screwed, pin 31 so that when the block 36 is forced, by pressure of the spring 37, against the inner face of the end-wall 30 of the cap 14, the contact-stud (or bolt-head) 40 in the block will be maintained out of engagement with the extension 33 of the screwed pin 31 when the latter is withdrawn, for example to a position in which the nut 34 is drawn against the inner face of the end-wall 30. By manipulating the pin 31 by turning it one way or the other so as to advance or withdraw it from the contact-stud 40, it can be brought into and out of engagement with that stud, thereby making, or breaking, respectively, the battery circuit.

The flanges 11 and 15 at the two ends of thecasing haveeach of them a series of holes 41 formed in them so that after the caps have been screwed into position there will be at leastonehole in a cap-flange 1-5 which will be in register with a hole in a casing-flange 11. Wires, such as 42, may be passed through so registering holes and officially sealed as at 43 so that the capscannot be removed by an unauthorized person. In Figure 1 a locking wire and seal have been shown at one end of the casing only, but it will be appreciated that similar locking means will be employed for oth ends when the torch is in use. The cap 13, carrying the reflector, can be adjusted before the looking or sealing wire is applied to give the desired focussing, but thereafter further focussing will be impossible by the user unless he is the person authorized to remove the seal.

In the second example illustrated in Figures 4: and 5, the construction of the casing, lamp socket, and switching means, is substantially identical with that of the corresponding parts described above in connection with Figures 1 to 3, with the exception that the circular flanges 11 and 15 are dispensed with. In Figures 4: and 5, the end-caps are each locked in position by means of a screwbolt which is screwthreaded into a socket 51 that is formed as a radial projection eX- tending. from the cap with the axis of the socket parallel with the axis of the casing. The inner end of the screw-bolt 50 is intended to be received in a corresponding socket 52 formed also as a radial projection from that part of the casing which is adjacent the cap, and the screw-bolt itself is such that it can be actuated only by means of a small key insertable through an aperture in outer end of the socket 51. This is en sured by inalzingthe length of the screw-bolt 50 such that when it is screwed home the level of head will be well within the screwthreaded recess in the socket '51. In order that the bolt 50 shall not be entirely with? drawn from the socket 51, a shouldered portion 53 is provided at the end of the socket 551 to engage with the outer end of the bolt 50.

The bolt 50 will be inserted within the socket 7 51 from its inner end before the parts are assembled.

The cap '13 in this seeond example of'the invention is of considerably larger diameter than that of the easing-.10 and is secured by means of a screwthread on to the outer end of a spherically formed part 54:, the inner end of which is formed with a cylindrical sleeve 55 which is'screwthreaded on to the end of the casing 10 and is so formed that it cannot be entirely withdrawn therefrom. The reflector 17 is pressed against the outer end of the part 54: by the cap 13 and the latter, together with the part 541 and its reflector, is

capable of endwise adjustment by means of x the screwthreaded connection between the at will by the user of the torch after the endcaps 13 and ll have been locked'in position.

The manner in which the cylindrical sleeve 55 1s screwthreaded onto the end vof the casing 10 so that it is adjustable but not detach-V able therefrom, is illustrated in detail in Fig ures 8 and 9. As shown in these figures, the

end of the casing 10 is screwthreaded at 110. Four lugs 111 are produced by sawcutting 1nwardly in a direction parallel to the axisof the casing 10, and these lugs are formed with overhanging shoulders 112 which are produced by cutting a groove 1 13 first of all throughout the whole periphery of the end of the casing 10 beyond the end of the screwthread 110. The lugs 11 are then bent inwardly, as is shown in the case of the two lugs on the right-hand side of Figure 9. The shoulder portions equivalent to 112 which would have been present on the sectors between the lugs 111, are, after the latter have been bent inwardly, cut ing 110. The sleeve 55 is then screwthreaded on to the end of the casing 10, and the lugs 111 are then forced outwardly into the position shown in the left-hand side of Figure 9 and in Figure 8. The outer end screwthread on the casing 55 can therefore be brought into contact with the shoulders 112, but not be-' yond, and by this means the sleeve 55 can be moved in both directions for a limited amount without being completely removable from the end of the casing 10. The hemispherical part 5a is secured at 1.54 by brazing or the like to the end of the sleeve 55 so that the part 54 is adjustable in an axial direction with the sleeve 55. As the reflector 17 is movable with the hemispherical portion 54, the beam of light from the bulb 18 can, by this means be focused. I

I claim 1. An electric torch comprising in combination a battery container which is completely closed in a gas-tight manner,-a gastight removable end-cap giving access to the interior of thecontainer, a lamp socket within the container near said end-cap, a reflector carried by said end-cap, a switch whereof a movable switch member is available from the outside of the torch but extends into the lnterior thereof in a gas-tight manner, looking means for preventing unauthorized removal of the end-cap,means for permitting endwise movement of the reflector along the torch for focussing the beam of light at will after the end-cap has been locked in position, and at least one stop for permitting only a limited endwise movement of the reflector along the torch and for preventing the parts from being separated until the container is I opened, otherwise than by removal of endcap.

2, An electric torch comprising in combination a tubular battery container which is completely closed in a gas-tight manner, a lamp socket within tight removable end-caps, one s of which serves for the insertion and removal of the battery, and the other aflords access to the lamp-socket and carries a reflector, a switch whereof a movable switch member is available from the outside of the torch but. ex-

away from the end of the casingmeans whereby '7 and at least one the container, two gastends into the'interior thereof also in a gastight manner, locking means for preventing unauthorized removal of the end-caps, means for permitting endwise movement of the reflector along the torch for focussing the beam "of light at will after the end-cap has been locked in position, and at least one stop for socket situated within one end of the container, a reflector carried by the lamp at that end and adjustable with the cap relatively to the socket, a switch member comprising a screw-threaded pin 7 passing through the other end-cap at the opposite end of the container and having a head available from the outside of the end-cap pin, radial projections on the casing adj acent the inner end of each cap, radial projections on the said caps which when the latter are in position will be opposed to those on the casing, cooperating apertures in the said pairs of projections for the reception of lockcontainer against unauthorized removal, stop for permitting only a limited endwise movement of the reflector along the torch, and for preventing the parts from being separated until at least one of the end caps is removed,

In testimony whereof I afiix my signature.

' JOHN LISTER.

for manipulating the the caps are locked tothe v lilo , iio 

